Several components aren't working

I sent my tablet to be fixed in dec. 2016 it was returned in Jan. 2017.It was working fine untill last week now it not lettinging me get too certain sites and changes from horizontal to vertical by it self and is difficult to stay on a site it will go back to the

Home page, it also will jump below the line when I'm texting . It basically does what it wants . When I didn't receive any form of what they fixed if anything.